According to the definition provided by the National Institute of Standards and Technology (NIST), cloud computing is a model enabling users to access, via a network, on demand and on a self-service basis, computing resources such as storage space, computing power, applications, software or services which are provided in a virtual and shared form.
According to NIST, there are three categories of service that can be offered via cloud computing: IaaS (infrastructure as a service), PaaS (platform as a service) and SaaS (software as a service). In particular, IaaS (infrastructure as a service) is the lowest level of service. It consists in offering access to a computing infrastructure which is virtualized, that is to say based on data centers (computing centers or data processing centers) composed of servers (also called “blades”) on which virtual machines are installed.
IaaS is mainly intended for business clients whose applications are hosted in secure data centers managed by the cloud service provider (CSP), these data centers usually being accessible on the internet via a secure connection to the private network of the business. As a general rule, the business client manages its infrastructure and computing resources via a web portal, and can thus rapidly adapt its computing resources to its peaks of activity and to the development of new applications.
The cloud computing services provided by the same service provider (CSP) in a number of countries (or different regions or states of a large country) generally use one or more data centers for each country or region. As a general rule, a client who has subscribed to a service offer in a given country, France for example, has his client account and his access to the service managed by a data center located in this country (country of origin). If this client travels to another country (visited country), for example the United States of America, and wishes to access his cloud services from the visited country, he must connect via his communication terminal (PC, tablet, or smartphone) to the network of this country—that is to say, for local internet access—and transmit a request for access to the service, which will be routed to the data center in the country of origin, even if a data center providing the same service exists in the visited country.
Because of the distance between the client's place of connection for access to the service in the visited country and the location of the server (data center) providing the service in the country of origin, the connection and use of the service from the visited country may cause a significant loss of quality of service (QoS), in terms of jitter, response time, network congestion and the like, as well as a possible increase in cost due to the inter-operator network connection. This is aggravated if the requested services are real-time services, such as communication services of the voice, video, conference, instant messaging, or other type.